Dyes used for detection of enamel and dentin caries

Procion dye

Stains enamel lesions but the staining becomes irreversible because the dye reacts with nitrogen and hydroxyl groups of enamel and acts as a fixative

Calcein Dye

Forms a complex with calcium and remains bound to the lesion

Brilliant Blue

Has also been used to enhance the diagnostic quality of fiberoptic transillumination

Sodium Fluorescein

Has been used as a plaque disclosing dye and was found to stain old plaque

Fluorescent Dye

Has been used in various studies as an aid in diagnosing incipient carious lesions